Ratchet-wrench



l? MMM;

` (No Modem' J. E. SNCLAIR.

Patented sept. 14, 1886.

W/T/ESSES N. Pnzna mwmhvmmm wanglmm 0.a.

4 T0 @ZZ whom it may concern:

UNITED STATES PATENT OFFICE..

JOHN E. SINCLAIR, OF VORCESTER, MASSACHUSETTS.

RATCHET-WRENCH.

SPECIFICATION forming part of Letters Patent No. 349,007, datedSeptember 14, 1886.

Application tiled April l0, 1886.

Be it known that I, JOHN E. SiNcLAiR, a citizen of the United States,residing at IVorcester, in the county of Vorcester and State ofMassachusetts, have invented certain Improvements in Ratchet-Wrenches,of which the following is a specification. j

My invention relates to the well-known class of ratchetwrenches in whicha pair of pawls is employed to engage with and to actuate theratchet-head, rotation being thereby imparted to the ratchet-head in onedirect-ion or the other, according as one or the other of the pawls isin engagement with the ratchet-teeth.

It particularly relates to the means of accomplishing the engagement anddisengagement of the pawls with the ratchet-teeth; and the inventionconsists of an improved mechanism for performing this operation, whichis illustrated in the annexed drawings.

Figure 1 is a plan View of a complete ratchet-Wrench to which myinvention is applied. Figs. 2 and 3 are partial views of `the same, witha covering-plate removedto show the internal arrangement of parts. Fig.4. is a sectional plan showing more completely the internalarrangements; and Fig. 5 isatransverse section taken on the line y,designed to illustrate Fig. 4 more fully.

The operation of the wrench is as follows: The socket-head B is adaptedto any mechanical purpose requiring its rotation, and is held in theframe A, free to rotate therein, except as the pawls C and D, byengaging with the ratchet-teeth, prevent it. These pawls are so mountedWithin the frame A as to admit of a limited oscillation in suitablecavities sunk in the substance of the frame A. Springs C D', Fig. 2, areplaced behind the pawls, acting to push them out into the positionsshown in Fig. 2. If, with the parts in these positions, the frame of thewrench be oscillated, as when in use, the head B must partake of themotion in both directions, being locked to the frame by the engagementof both pawls. If by any means one ofthe pawls be thrown back out ofengagement with the ratchet, as is the pawl C inV Fig. 3, and the otherpawl, D, is free to act, then oscillation of the frame will cause anintermittent rotation of the head B, the pawl D acting in a well-knownmanner. Likewise, it is evident that if the posit-ion of the pawls be(No model.)

reversed, then rotation of the head will take place in an oppositedirection.

To provide an improved means of setting the pawls to produce theabovedescribed re- Suits is the object of my invention. The mechanismfor accomplishing this consists of a plate, E, adapted to slidelongitudinally in a channel su-nk in the material of the frame A, insuch location and so arranged that its ends come alternately in contactwith the pawls, and of a shaft, F, upon the end of which is formed aneccentric or crank pin, F. The plate Eis provided with aslottedaperture, E, Fig. 5, so arranged and of such shape as to admit thecrank-pin F4, in the manner exhibited in Figs. 4 and 5. The shaft F iscontained within the handle ot' the wrench, and is free to turn axillarytherein, the milled button-head FL being provided for this purpose. Itis evident that rotation of the shaft willy cause (by means of the crankor eccentric pin F working in the slot E) the plate E to traverselongitudinally in its groove, a half-revolution of the shaft bringingthe pin F into the dottedline positionsff, Fig. 5, giving to the plateits extreme of travel from side to side. The relation of the position,the length, and the travel of the plate E to the pawls is such that oneor the other of the pawls is pushed back out of range of engagement withthe ratchetteeth when the plate is at either extreme of vits travel.Vhen one pawl is thus withdrawn from action, the. other is advanced toaction by means of the spring behind it, as illustrated by Figs. 3 and4, which show one position of the parts. It is evident that ahalf-revolution of the shaft will reverse the position and actionof theparts. If the shaft be turned into the position shown in Fig. -that is,to bring the plate E to a middle position of its travelboth pawls willbe engaged with the gear-teeth at the same time, and the socket-head B,restrained from turning independently of the frame A, becomes a xturewithin it. This position of the parts is shown in Fig. 2. Thispawl-operating mechanism accomplishes also the locking of the plate ineither extreme position of its travel, so that the pawl under the actionof the spring, aided by the jar which back the plate and come intoaction prematnrely. This locking results from the described theinstrument receives in use, may not thrust arrangement of the parts, andfrom proportioning them so that the crankpin l?" shall travel overslightly more than a semicircle, coming to rest against the lower end ofthe slot in the plate E-a position slightly over and beyond the center.Pressure ol' the paivl against the plate will tend to rotate the shaftby carrying the pin still farther beyond the center, which motion cannottake place, because the crank-pin has reached the end of the slot. Thepawl is thus securely locked until released by tnrning the button-headF2. Another advantage from this device is, that as the pawls aredepressed and the springs resist with increasing force this iscounteracted by the increasing leverage of the crank-arm as the erankpmapproaches the center, the inechanical advantage and disad vantagesonearly balancing` one another that no perceptible increase of resistanceis l'elt in operating the but tonhead F2. A special advantage from thisdevice is, that the pawls can be operated and the rotation reversed at adistance from the rotating piece. .ln this way a rotation can beproduced among the revolving wheels of various machines when the commonmethod of reversing the pawls would be dangerous. As far as l am aware,this cannot be practically accomplished by any other ratchet mechanismhitherto known.

I am not limited in my invention tothe precise forni or arrangementofmechanism shown, which is only one convenient application of it.

plication to any double-paw] ratchet meehan` My invention essentiallyconsists ot' the ap ism of a shaft provided with a cranl-z or eccentricadapted to operate the pawls alternately through the medium of a slidingplate or an equivalent.

I claim as my invention the following:

l. The shaft F, having an eccentric or crank pin, and the sliding plateE, adapted to be operated by the eccentric or crank pin, in combinationwith a pair of pawls operating together, substantially as and for thepurpose specifiedn 2. 'lhe eol1ibination,\vith the socket-head of aWrench having :1.1'atchet-ivhccl and a pair of pawls, ot' a shaft havingmeans of operating the said pawls, the shalt projecting through theframe containing thcsaid socket-head, sul)- stantially as and for thepurpose specified.

3. The combination, With a pair of pawls, of a shaft provided with aVcrank-pin and a slotted plate adapted to be operated by the saidcrank-pin, for the purpose of controlling the said pawls, substantiallyin the manner and for the purpose specified.

4. The combination, with a pair of pawls, of a shaft provided with acrank-pin and a sliding plate having a slot so adjusted to the travelot' the crank-pin that the plate will be locked at cach end of itstravel by the crankpin goingl beyond the center and striking the end ol'the slot, substantiallyY in the manner and Yfor the purpose specified.

JOHN ll. SINCLA l ll. `\`i"itnesses;

Mimn'r'ar S. Smetana, Y CLARA (l. IHlaLrs'.

